Fix: Remove reference to non-existent agent module in CLI

[codegen-sh]

Description

This PR fixes an issue where the CLI is trying to import a non-existent module codegen.cli.commands.agent.main. This was causing errors when users tried to run commands like codegen init or codegen update.

Changes

• Removed the import of agent_command from codegen.cli.commands.agent.main
• Removed the reference to agent_command in the main.add_command section

Testing

This change should allow users to run basic codegen CLI commands without encountering the ModuleNotFoundError: No module named 'codegen.cli.commands.agent' error.

Related Issues

This fixes the issue reported in Slack where a user was unable to run codegen init or codegen update due to this missing module.